射影几何：长度信息丢失 A is half the size of B C is half the size of B B A Hangzhou D1 ianzi Univer容ity杭州电子H技大年 School of Computer Science and Technology算n年m年Hangzhou Dianzi University 杭州电子科技大学 School of Computer Science and Technology 计算机学院 周文晖 A is half the size of B C is half the size of B